Shock absorber for drift recording instruments



Ju ne 28, 1938. J. w. cuLBE TsoN- 22 SHOCK ABSORBER.FOR DRIFT RECORDING INSTRUMENTS Original FiledApril 3, 1935' 2 Sheets-hes; 1'

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I I6 I IN very TOP- J05 IM'Cu BEETS A A T Toe *5 Y Patented June 28, 1938 I w I UNITED STATES. PATENT OFFICE SHOCK ABSORBER FOR DRIFT RECORDING INSTRUMENTS Joe W. Culbertson, West Hollywood, Calif., as- I signor to Technical Oil Tool Corporation, Ltd.,

' a corporation of California Original application April 3, 1935, Serial No. 14,479. Divided and this application October 23, 1936, Serial No. 107,211

' 11 Claims. (01. 33-2055) My invention relates to shock absorbers for tional-views taken on the lines 6-6 and 1-1 drift recording instruments and is a division of of Fig. 5. my co-pending application for drift recording My invention in the embodiment herein shown apparatus, Ser. No. 14,479, flied April 3, 1935- comprises a receptacle [5 adapted to contain an t s a pu po e o y p se invention to p oinstrument for recording the drift or deviation 5 vide a shockabsorber by which any drift o of a well hole from the vertical, such as the ing instrument, and particularly one of the deliinstrument embodied in my co-pending applicate character embodied in my (B -pe i g P- cation above referred to. This instrument inplication above referred to, is effectively prod s a plumb bob type of angle marker A for tected against dama r s an f the for e ,marking the angle of deviation on a chart 0 10 of p t Produced y the instrument housing when the latter is moved into engagement with tr k ng the a Projections of an Open hole the marker by a preset time controlled actuatdrill pipe during descent and the final impingeing mechanism t Shown) v ment thereof at the point of stoppage, whether The receptacle 5 is contained in an elongated the instrument is dmpped 1Wered an tubular metal housing |6, the lower end of which 15 Open 1119 drill Pipet is closed by a stem ll threaded into housing It is alSO- a p p my invention to P I and provided with extension i8. A rubber buffer vide a shock absorber of the character abovedehieek 9 reposes on the inner end of th t scribed which is Particularly adapted for use in sion 18 and projects into the lower end of a conjunction with any drift recording instrument spring 20 for the purpose of preventing fuii employing a, plumb bob type of angle marke pression of the spring and thus avoiding the rea Where it is neeeSsel'y to Secure an accurate sultant metal to metal contact of its convolutions recordation in. the Short-e51; time possible. and consequent trwsmission of shock to the A team: necessary secure quick accurate elements connected to and contacting with the 25 -Iee0rdet1n 15 that the free. swingmg angle spring. A leather cup 2| is secured to the lowermPrker be bmught quickly to i w end of the block l9, and it is of such diameter .still after the instrument reaches its limit of as to frictionany retain itself within the housing descent in a Weli- By means of my shQck l6 to'prevent the spring from dropping out of o be t instrument i not only efleetivelv the housing when the extension i8 is removed. tected against damage, but Such li move- The receptacle [5 is situated in the housing l6 ments as the angle marker is 511bieted Incident above the spring 20, and its lower end is closed to my device absorbing shocks, are quickly by a plug 22 against which bears the upper end dampened to bring the angle marker as a whole f the spring The upper end f the receptacle is p y to a standstillclosed by a cap 23 connected to the lower end I w ll es y one 010m shock of a cylinder 24 through a stud 25 (Fig. 7). sorber for drift recording instruments embody- Threaded upon t st d i a, cup-shaped nut 26 y invention and Will then P out the and this nut is releasably locked against accinovel features thereof n claims dental unscrewing by a ball 21 in a pocket 28 Fi s- 1 and 1a re figures, one a n uat on of a plurality of radial grooves 30 in the conof the other, showing in side elevation with the fronting face of t cap 23 The t 26 has a housing thereof in'section, one form of shock reduced portion 2 upon which cap 3| i absorber embodying my invention in association threaded and locked by a. pin 32. with drift ecording instrument. Extending into the cap 3| is a coupling pin 5 Figs- 2 and 3 a figure Showing e shock ab- 33 having a collar 34 threaded therein and rosorber'partly in elevation and partly in section, tatably ounted in the cap by means of balls and two positions which the parts thereof are 35. Thus, the coupling pin is rotatable relative adapted to occupy when in actual use. to the cap and the elements connected thereto. 4 is an enlarged fragmentary View h The upper end of the coupling pin is threaded 5 ing in longitudinal Sectionthe upper P01191011 of into a head 36 threaded, in turn, into and closing shock absorbr' the lower end of the cylinder 24. The elements F 5 is a View Similar to 2 and is 0011- just described constitute a rotatable connection tinu on h between the cylinder and the receptacle 15 which F 6 and 7 are enlarged ragmentary secprevents unscrewing of the receptacle from the 55 I the p y g drawings: and a spring 29 pressing the ball into any one 40 to a pair of reversely disposed. cup washers 4| preferably made of leather.

The rod 37 is bored to form a duct 42 which functions to by-pass air from one side of the piston to another, and the amount of air so by-passed is controllable-by a metering pin 43 threaded in the lower end of the rod and formed witha port 44. The diameter of this port determines the rate of air flow .through the pin, and by substituting similar pins having ports of other diameters the rate of airflow can be metered as required.

As best shown in Fig. 5, the piston rod 31 extends upwardly through a stumng box comprising a packing nut 45 and a gland 46 threaded in the cylinder 24 and receiving a spring 41 which is adjustable by the nut to compress packing 48 contained in the gland. The rod at its upper end is connected to an upper stem 49 formed of solid metal and threaded in the upper end of the housing 16 (Fig. 4) through the medium of reduced extension 50. This extension carries a collar 50, and a pin 5! extends through the collar and through a head 52 to provide a pivotal connection between the two.

This pivotal connection allows'that freedom of movement of the cylinder 24 necessary to permit self-alining thereof in the housing H6. The rod 3'8 is threaded in the lower end of the head 52 and secured by a. pin 53, while the head is formed with a flange 54 against which the upper end of a spring 55 abuts. A buffer sleeve 55 formed-of rubber surrounds the rod 37 contiguous to the.

head 52 to prevent complete retraction of the spring and the consequent metal to metal contact of the convolutions thereof.

Lower and upper sets of spring arms 57 and 58, respectively, are secured tothe stems ill and 49, respectively, for the purpose oicentering the housing 86 when it'comes to rest after being dropped or loweredin a drill pipe. A spear 59 is connected in any. suitable manner to the lower end of the stem El. As the spring arms and spear form no part of the present invention the manner in which they are connected to the stem is immaerial.

In the operation of the shock absorber, the parts thereof normally occupy the positions illus trated in Figs. 1 and 1 in which the receptacle l5 containing the drift recording instrument is resiliently sustained within the housing between the springs 20 and 55. When the housing is lowered or dropped into a drill pipe or open hole with the spear end lowermost, the spear strikes whatever wall or pipe projections are disposed in'its path to, in each instance, momentarily check descent of the housing. With each checking movetained by the air above the piston being compressed with each downward movement of the cylinder and allowed to bleed through the metering port 44 to the lower side of the piston at a predetermined rate depending upon the diameter of the port. The spring 20 likewise'resists movement of the cylinder downward, but its primary purpose is to constantly act to restore the cylinder to its normal elevated position. Upward movement of the cylinder and receptacle as a result of expansion of the spring 20, is resisted by the spring 55 and the air below the piston to decelerate such movement in accordance with the bleeding of air to the upper side of the piston. The uppermost position of these elements is shown in Fig. 3.

Thus it becomes manifest that my shock absorber embodies a resilient means which are the springs 20 and 55, and a pneumatic or fluid means which comprises the cylinder and piston, the two means coacting to absorb each shock to which the housing is subjected during descension into a well, in a manner to prevent its transmission to the drift recording instrument to the extent of damaging the instrument.

Once the housing reaches its lowermost pointof descent such as when the spear strikes the bottom of an open hole or the stem of a drill bit in a drill'pipe, the whole housing is subjected to a blow the force of which causes rapid reciprocation .of the cylinder and receptacle between the springs thereby subjecting the angle marker of the instrument to a like motion. As long as the angle marker is vibrating in this manner an accurate recordation cannot be made, hence, if time is the essence in making a recordation such as in rotary drilling, it is necessary that bodily movement of the angle marker be dampened as rapidly as possible. der and piston acting as they do to yieldingly restrain movements of the receptacle in both directions, reciprocation of the receptacle is soon dampened to bring the angle marker quickly to a standstill following the blow to which the housing is subjected when reaching its limit of descent.

Depending upon the depth of the well in which a drift recordation is taken, which in turn determines the speed of descent of the housing and the resultant force with which it strikes the bottom of the well or the drill pipe, determines the size of the metering pin to be used in the piston. In other words, as the force of impact increases the diameter ofthe pin port used is decreased in order to decelerate bleeding of air from one side of the piston to the other. Naturally this increases the pressure to which the air in the cylinder is compressed by the piston and, hence, the resistance oflered to movement of the cylinder and receptacle is increased accordingly.

Although I have herein shown and described only one form of shock absorber for drift recording instruments embodying my invention, it is to be understood that variouschanges and modifications may be made herein without departing from the spirit of my invention and the spirit and scope of the appended claims.

I claim 31- V.

1. In combination; a tubular housing closed at its ends; a receptacle movable axially in the housing; pneumatic means disposed in the housing between said receptacle and the upper end of the housing for cushioning the receptacle against axial shock in both directions; and resil ient means in the housing between the lower end Through provision of the cylinthereof and said pneumatic means for aiding the absorber in the housing having a piston part anda cylinder part, one of said parts being secured to the housing and the other secured to the receptacle.

3. In combination; a tubular housing closed at its ends; a receptacle movable axially in the housing and adapted to contain a drift recording instrument; a double a'cting fluid shock absorber in the housing having a piston secured to one end of the housing; and a cylinder receiving the piston andsecured to the receptacle.

4. In combination; an elongated tubular housing closed at its ends;a receptacle movable axial- 7 ly in said housing; a closed cylinder secured at its lower end to said receptacle and disposed in the housing above the receptacle; a piston in the cylinder secured to the upper end of the housing and having a duct therethroughto allow air to I so pass from one side of the piston to the other; and a spring in the housing beneath the receptacle for urging the cylinder and the receptacle upwardly to a predetermined axial position with respect to said piston. c g

5. In combination; an elongated tubular housing closed at its ends; a receptacle movable axially in said housing; a closed cylinder secured at its lower end to said receptacle and disposed in the housing above the receptacle; a piston in v the cylinder secured to the upper end of the housing and having a duct therethrough to allow air to pass from ,one side 01 the piston to the other; and a second springbetween the cylinder and the upper end of the housing.

6. In combination; a tubular housing closed at its ends; areceptacle movable axially in the the receptacle and thelower end or the housing.

" housing and adapted to contain a drift recording instrument; a closed cylinder siidable in the housing above the receptacle; a rotatable connection between the cylinder and receptacle; a piston in the cylinder; a rod fixed to the piston and extending through the upper end of thecylinder; means for pivotally securing the rod to the upper end or the housing; a duct in the rod leading from one side of the piston to the other;

a metering pin in the duct; and Ya spring between I. Incombination; an elongated tubular housing closed at its ends; areceptacle movable axiallyinthehousingandadaptedtocontainadriit mecording I instrument; a closed cylinder siidable in the housing above the receptacle and fixed to the receptacle; a piston in the cylinder; a rod fixed to the piston; extending through the upper end of the cylinder and secured to the upper end of the housing; a duct in the rod leading from one side of the piston to the other; a metering pin removably fitted in the duct; and a spring inder; means for pivotally securing the rod tothe upper end of the housing; a duct in the rod leading from one side of the piston to the other; a metering pin in, the duct; and a second spring between the upper end of the cylinder and the upper end of the housing.

9. In combination; an elongated tubular housing closed at its ends; a receptacle movable axially in thehousing and adapted to contain a drift recording instrument; a closed cylinder siidable in the housing above the receptacle; a a

rotatable connection between the cylinder and receptacle; a piston in the cylinder; a rod fixed to the piston and extending through the upper end of the cylinder; means for pivotally securing the rod to the upper end of the housing; a duct in the rod leading from one side of the piston to the other; a metering pin removably fitted in the duct; and bufler members of nonmetallic material correlated to the springs ior preventing complete contraction of the springs.

10. In combination; a tubular housing closed at its ends; a drift recording instrument movable axially in the housing and including a plumb bob type oi. angle marker; resilient means in ,the housing at opposite ends of said instrument for cushioning said instrument against axial shock; and means in the housing for dampening axial vibrations of said instrument whereby the angle marker is quickly brought to a standstill following cessation in motion of the housing.

11. In combination; a tubular housing; a receptacle movable axially in the housing and adapted to contain a drift recording instrument; pneumatic means disposed in the housing between the receptacle and one end or the housing; and resilient means disposed in the housing between the receptacle and the other'end of the housins. said pneumatic and resilient means being constructed and arranged to coact in cushionins the receptacle and the instrument against 

